VISUAL CORTICAL PROCESSING OF GENICULOCORTICAL BURSTS

（申请人的摘要）该提议旨在理解本发明的实施例。 视觉信息进入视觉皮层网络的机制 并且在外侧膝状体的不同操作模式期间被处理 原子核外侧膝状体核的单个神经元在 两种不同的模式：“中继”模式和“突发”模式。中继模式主要发生在 在警戒状态下，通过这个核团的突触传递是高度 有效相比之下，突发模式主要与 注意力不集中、困倦和睡眠，以及通过大脑皮层的突触传递。 丘脑是抑郁的。为了理解这一点， 这些丘脑模式的潜在机制及其在视觉感知中的作用， 和丘脑爆发与注意力机制有关。但 在我们理解丘脑的知觉后果的关键环节 爆炸仍然没有被探索：我们不知道爆炸的丘脑的命运 在膝状皮质突触处产生脉冲。我们的初步工作 躯体感觉系统已经显示出对突触影响的有效增强， 丘脑皮层爆发到一类皮层抑制神经元上。这个结果， 如果适用于膝皮质视觉系统，将影响电流 思考膝状皮质爆发在视觉处理中的作用。的 拟议的实验将这些结果扩展到视觉丘脑皮层 系统和将（1）检查视觉引起的突触影响， “自发”爆发性膝状皮质冲动对兴奋性和抑制性 第4层的视觉皮层群体，以及（2）检查皮层内 由自发的和视觉引起的兴奋的扩散 膝状皮质爆发所有实验都将在清醒的受试者中进行 使用新的细胞外和细胞内多电极方法。的 膝状皮质投射神经元和视皮质神经元的活动 视觉皮层内的不同类别将同时进行研究， 这些识别出的神经元之间的相互作用将使用以下方法进行分析： 突触后电位的互相关和尖峰触发平均。我们 假设膝状皮质冲动的爆发产生了增强的 视觉皮层网络内兴奋的激活和传播。这些 数据将提供一个独特的观点，视觉处理的膝状皮质网络 在自然条件下的清醒状态下进行研究。

DESCRIPTION: (Applicant's Abstract) This proposal is aimed at understanding the mechanisms by which visual information gains access to visual cortical networks and is processed during different operational modes of the lateral geniculate nucleus. The individual neurons of the lateral geniculate nucleus operate in two distinct modes: "relay" mode and "burst" mode. Relay mode occurs primarily in the alert state, and synaptic transmission through this nucleus is highly effective. In contrast, burst mode has been primarily associated with inattention, drowsiness, and sleep, and synaptic transmission through the thalamus is depressed. Considerable effort has gone into understanding the mechanisms underlying these thalamic modes and their role in visual perception, and thalamic bursts have been linked to mechanisms of attention. However, a crucial link in our understanding of the perceptual consequences of thalamic bursting has remained unexplored: we do not know the fate of bursting thalamic impulses at the geniculocortical synapse. Our preliminary work in the somatosensory system has shown a potent enhancement in the synaptic impact of thalamocortical bursts onto a class of cortical inhibitory neuron. This result, if applicable to the geniculocortical visual system, would impact current thinking on the role of geniculocortical bursts in visual processing. The proposed experiments will extend these results to the visual thalamocortical system and will (1) examine the synaptic impact of both visually elicited and "spontaneous" bursting geniculocortical impulses on excitatory and inhibitory visual cortical populations of layer 4, and (2) examine the intracortical spread of excitation that results from both spontaneous and visually elicited geniculocortical bursts. All experiments will be performed in awake subjects using novel extracellular and intracellular multi-electrode methods. The activity of geniculocortical projection neurons and visual cortical neurons of different classes within visual cortex will be simultaneously studied, and interactions among these identified neurons will be analyzed using methods of cross-correlation and spike-triggered averaging of post-synaptic potentials. We hypothesize that bursting geniculocortical impulses generate an enhanced activation and spread of excitation within the visual cortical network. These data will offer a unique view of visual processing by geniculocortical networks studied under natural conditions in the awake state.